08-10-2014, 04:13 PM
Forced vibration tests are performed on a reinforced concrete (RC) moment resisting frame (MRF) building with unreinforced masonry (URM) infill walls to determine its dynamic properties namely, the fundamental translational and torsional natural periods, the corresponding mode shapes and the structural damping. This three-storey building lies in the seismic zone III of India. An eccentric mass-shaker is used as force generator operating between 200 and 1400 cps, is used to apply a high level force and shake table for low level harmonic force at desired frequencies. The building is analytically modelled using the FEM package, ETABS. Three models namely Bare frame model, Model with infill walls modelled as diagonal struts without incorporating the effect of openings and Walls modelled as diagonal struts after considering the effect openings struts. The dynamic properties of the building as derived using these models are compared with the experimentally obtained ones. The material properties used in the modelling, i.e., modulus of elasticity of brick masonry and reinforced